Patent Document 1 discloses an electronic apparatus noise measurement method for a distribution estimation apparatus for experimentally estimating the distribution of radiated emissions inside/outside the housing of an electronic apparatus.
Patent Document 2 discloses an apparatus for measuring an S parameter using a three-port network analyzer.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 6-43197
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2004-361380
However, an apparatus having the configuration disclosed in Patent Document 1 or 2 is not suitable for determining the source of noise on a printed circuit board provided in the housing of an electronic apparatus or separately detecting common-mode noise and normal-mode noise.